1. Field of the Invention
The present invention relates to information storage and display systems utilizing rotating storage drives, and more particularly, to video recording systems that record video data streams.
2. Description of the Related Art
Digital video recorders provide the capability of concurrently recording incoming streaming video data using hard disk drive technology and playing back previously recorded video data. As currently available, a digital video recorder receives incoming streaming video data from the output interface of a standard set-top box configured to receive the broadcast signals from a multiple-service operator (MSO), such as a cable provider, and the output of the digital video recorder is transmitted directly to a display device, such as a television. Such standard set-top boxes typically have only one input interface and one output interface. In response to commands from the user, the digital video recorder transmits to the display device either the incoming streaming video data from the output of the set-top box or the previously recorded video data.
Because currently available digital video recorders receive their input from the standard output interfaces of currently available set-top boxes, such digital video recorders require numerous components which are duplicates of components already utilized by the set-top boxes. For example, in order to view digital broadcast channels using a standard television, a set-top box must convert the input digital broadcast channels into output video signals which conform to a standard format for composite video, such as the National Television Standards Committee (NTSC) standard. This standard output format is generated by various components in the set-top box, such as a transport demultiplexer (xe2x80x9cDEMUXxe2x80x9d), an MPEG decoder, and an NTSC encoder. Additionally, the output from the set-top box may contain information from an on-screen display module. This information may represent programming information. The information may also list specialty capabilities such as picture-in-picture, which the user can enable. A digital video recorder compatible with such a configuration must convert the NTSC composite video received from the set-top box back into digital form for storage, and then reconvert again to NTSC composite video to play back the stored video signals. Therefore, just as the set-top box did, the digital video recorder requires a transport DEMUX, an MPEG decoder, and an NTSC encoder, which effectively duplicate components and functions of the set-top box.
Similarly, currently available digital video recorders also include a standard input interface that receives the output from the set-top box, and a modem that is configured to receive electronic program guide information from the MSO. Both the input interface and the modem of the digital video recorder duplicate components or functions found in currently available set-top boxes.
There is, therefore, a need to provide the capabilities of currently available digital video recorders and set-top boxes, while also enabling the reduction of the redundancy of functions and components among these digital video recorders and set-top boxes.
The present invention may be regarded as a digital video recorder connectable to a set-top box that includes a video input interface that receives a broadcast signal and a video output interface that provides an output video data stream to a display device. The set-top box has at least one auxiliary interface that supports connection of the digital video recorder to the set-top box, a microprocessor that generates a command in response to user input initiating a playback interval, and a multiplexer coupled to the video output interface and the microprocessor. The set-top box is configured to (a) use the video input interface to generate a real-time video signal, (b) recognize connection of the digital video recorder to the set-top box and subsequently continuously provide the real-time video signal to the digital video recorder, and (c) receive a recorded video signal from the digital video recorder during the playback interval. The digital video recorder comprises at least one recorder interface for connecting the digital video recorder to the at least one auxiliary interface of the set-top box, the at least one recorder interface continuously receiving the real-time video signal from the set-top box, and providing the recorded video signal to the set-top box during the playback interval. The digital video recorder further comprises a disk, and a video data stream manager that responds to the real-time video signal and provides a first video stream to store a selected video segment on the disk. The video data stream manager, in response to the command from the microprocessor, receives a second video stream based on the selected video segment stored on the disk to generate the recorded video signal. The multiplexer of the set-top box selects the real-time video signal during a real-time interval and selects the recorded video signal during the playback interval to generate the output video data stream that is provided to the display device.
The present invention may also be regarded as a method for viewing a real-time video signal during a real-time interval and for viewing a recorded video signal during a playback interval. The method connects at least one recorder interface of a digital video recorder to at least one auxiliary interface of a set-top box. The set-top box includes a video input interface, a video output interface, a microprocessor that generates commands in response to user input, and a multiplexer coupled to the video output interface. The digital video recorder includes a disk and a video data stream manager. The method recognizes the connection of the digital video recorder to the set-top box, and generates the real-time video signal in response to a broadcast signal received by the video input interface of the set-top box. The method provides the real-time video signal to the multiplexer and to the video data stream manager via the at least one auxiliary interface and the at least one recorder interface. The method provides a first video stream in response to the real-time video signal to store a selected video segment on the disk, and receives a second video stream in response to the command from the microprocessor to generate the recorded video signal. During the playback interval, the method provides the recorded video signal to the multiplexer via the at least one recorder interface and the at least one auxiliary interface. The method transmits an output video data stream to a display device, the output video data stream generated by the video output interface in response to a selectively transmitted video signal from the multiplexer. The multiplexer selectively transmits the real-time video signal during a real-time interval to the video output interface and selectively transmits the recorded video signal during the playback interval to the video output interface to generate the output video data stream that is provided to the display device.